The truncated MyD88s negatively regulates TLR2 signal on expression of IL17-1 in oyster Crassostrea gigas

Siqi Fan; Weilin Wang; Jialuo Li; Wanqing Cao; Qing Li; Shasha Wu; Lingling Wang; Linsheng Song

doi:10.1016/j.dci.2022.104446

The truncated MyD88s negatively regulates TLR2 signal on expression of IL17-1 in oyster Crassostrea gigas

Dev Comp Immunol. 2022 Aug:133:104446. doi: 10.1016/j.dci.2022.104446. Epub 2022 May 13.

Authors

Siqi Fan¹, Weilin Wang¹, Jialuo Li¹, Wanqing Cao¹, Qing Li¹, Shasha Wu¹, Lingling Wang¹, Linsheng Song²

Affiliations

¹ Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Diseases Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
² Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Functional Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Diseases Prevention and Control, Dalian Ocean University, Dalian, 116023, China. Electronic address: lshsong@dlou.edu.cn.

PMID: 35569578
DOI: 10.1016/j.dci.2022.104446

Abstract

Toll like receptor (TLR) signaling plays a key role in the innate immune recognition and inflammatory regulation in both vertebrates and invertebrates. The expanded TLR signaling components, including 83 TLRs and 10 MyD88s, have been reported in the genome of the Pacific oyster Crassostrea gigas. In the present study, one endogenous TLR (designated CgTLR2) and two MyD88s (including a full-length CgMyD88-2 containing intact TIR domain and Death-domain, and a truncated CgMyD88s with only TIR domain) were identified from oyster C. gigas. CgTLR2 was highly expressed in haemocytes, especially in granulocytes. The recombinant protein of the extracellular LRR domains of CgTLR2 recognized and bound a variety of PAMPs with the strongest binding capability to LPS. The recombinant protein of intracellular TIR domain of CgTLR2 was able to bind the recombinant proteins of rCgMyD88-2 (K_D = 1.96 × 10^-9 M) and rCgMyD88s (K_D = 4.84 × 10^-8 M), with higher affinity towards rCgMyD88-2. After Vibrio splendidus stimulation, the mRNA expression levels of CgTLR2 and CgMyD88-2 were rapidly up-regulated at early stage of immune response (from the 3rd hours after V. splendidus stimulation), while that of CgMyD88s did not change until 24 h post stimulation. When CgTLR2 was knocked-down by siRNA interference, the expression levels of CgMyD88-2 and CgMyD88s decreased significantly, concomitant with the down-regulation of expression of CgIL17-1. After the expression of CgMyD88-2 was interfered, the expressions of CgMyD88s and CgIL17-1 were all decreased. In contrast, after the expression of CgMyD88s was interfered, the expressions of CgMyD88-2 and CgIL17-1 all increased. The results showed that CgMyD88s played a negative role in the regulation of CgTLR2 on inflammatory factor CgIL17-1.

Keywords: Crassostrea gigas; IL17-1; Immune regulation; MyD88; TLR signal.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Crassostrea* / genetics
Hemocytes
Immunity, Innate / genetics
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Toll-Like Receptor 2 / genetics
Toll-Like Receptor 2 / metabolism
Toll-Like Receptors / metabolism

Substances

Recombinant Proteins
Toll-Like Receptor 2
Toll-Like Receptors